Venous diseases reportedly affect between 500,000 and 1,000,000 persons per year. Venous diseases affect a much younger age group than heart or lung diseases, or most cancers. Due to their chronic nature, the diseases remove people in the prime of their earning potential from the work-force. The resulting cost to society is enormous. Past efforts to improve the quality of life, let alone restore work-force capacity, for affected persons have been difficult as discussed in J Mayberry, G Moneta, L Taylor, J Porter, Nonoperative Treatment of Venous Stasis Ulcer, Venous Disorders, 1991.
Within the last ten years there has been a renewed interest in the study of venous diseases by both physicians and scientists. This interest can generally be attributed to the application of ultrasound imaging techniques to the study of venous diseases.
To assist a vascular surgeon, it is desirable to evaluate a patient's venous anatomy prior to an operation. To further assist the surgeon, it is desirable to create a "map" of the underlying venous anatomy on the relevant area of the patient's skin. Currently, there are two procedures available to accomplish these tasks. The first is an invasive technique called a venogram. The procedure involves injecting a radioactive dye into the patient's veins and then taking an x-ray of the relevant area. The anatomy is visualized on the x-ray film, thus providing the surgeon with evaluative material, but no marks can be accurately placed on the patient's skin from the technique. Moreover, because of its invasive nature, a venogram creates a risk of adverse effects to the patient.
The second procedure currently used is a non-invasive technique that utilizes ultrasound imaging equipment and a conventional ink marker. The ultrasound equipment requires a transmission gel to be spread on the patient's skin to fill the air space between the skin's surface and the surface of the ultrasound transducer. The transducer transmits and receives ultrasound pulses to and from the patient's tissue. The presence of the transmission gel, however, prevents a mark from being directly placed on the patient's skin. As a result, the procedure requires two technicians; one technician operates the ultrasound transducer while the other technician wipes away the transmission gel and marks the skin corresponding to the underlying venous anatomy with the ink marker. A further drawback of the procedure is that it does not allow for a continuously connected line to be marked on the limb of a patient. Rather, marking occurs at two inch intervals over the length of a limb resulting in a line of dots. Only after the dotted line has been marked and the limb wiped clean of the transmission gel can the dots be connected to form a continuous line. Thus, the currently used non-invasive method is cumbersome, time-consuming and expensive because of the necessity of utilizing two technicians. As a result, "mapping", although desirable, is often an unemployed tool.
The present invention addresses the problems associated with the currently used methods by providing a non-invasive efficient transfer of clinical information from the ultrasound technician to the vascular surgeon. The present invention requires only one ultrasound technician to "map" the venous anatomy of a patient. The invention eliminates the need to first wipe away the layer of transmission gel required to operate the ultrasound transducer before marking the area of skin corresponding to the underlying venous anatomy. In addition, the ink used in the present invention is quick-drying and water insoluble, and, therefore, is not disturbed by the ultrasound transmission gel. As a result, the present invention leaves an ink mark on the patient's skin which will remain for several days until the surgical procedure can be carried out. Being non-invasive, the invention also does not pose an independent risk to a patient. Therefore, the present invention provides a safe, quick and efficient method for "mapping" the venous anatomy of a patient that will aid the vascular surgeon.